Using an image forming apparatus that does not have a duplex printing unit for enabling printing on both sides of paper, duplex printing can be achieved as follows, for example. Printing is first performed on one side of paper, and the printed paper is ejected onto a catch tray. Next, a user sets the printed paper into a feeder tray again, and then printing is performed on the other side of the paper. Thus duplex printing can be completed.
However, when the user reinserts the printed paper into the feeder tray, he/she has to decide whether the other side of paper to be printed on should face up or down in the feeder tray. Thus, the reinsert operation is complicated for the user.
In view of this, there has been proposed that instruction on how to set the printed paper is provided as an image displayed on a display device for the user (as shown in JP-A-H11-20272, for example). Thereby the user's burden when reinserting the printed paper into the feeder tray can be reduced.
However, printing may be performed using two-faced paper of which two sides are distinguishable. In the case that printing is thus performed using two-faced paper such as paper having a company logo on its one side, the user may have to decide whether the side of the paper to be first printed on should face up or down when he/she first sets paper into the feeder tray. For example, the user may have to decide whether the side with a company logo should face up or down in the feeder tray, in order to enable printing of odd-numbered pages (e.g., Page 1, Page 3 and Page 5) thereon. This is bothersome to the user.
Thus, there is a need in the art to provide an image forming system and a display control method to be used therein for enabling a user to set sheets of paper readily.